BUSINESS SEGMENTS Reconciliation from Segment Totals to Consolidated (Details) - USD ($) $ in Millions	3 Months Ended			6 Months Ended	9 Months Ended
	Sep. 30, 2017	Jun. 30, 2017	Sep. 30, 2016	Jun. 30, 2017	Sep. 30, 2017	Sep. 30, 2016
Segment Reporting, Revenue Reconciling Item [Line Items]
Sales to unaffiliated customers	$ 1,872		$ 1,709		$ 5,373	$ 4,769
Intersegment sales	179		233		544	692
Third party and intersegment revenue, net	2,051		1,942		5,917	5,461
Net contribution to earnings	201		298		639	740
Interest expense, net of capitalized interest	(98)		(114)		(297)	(323)
Earnings from continuing operations before income taxes	103		184		342	417
Income taxes	27		(22)		(31)	(64)
Earnings from continuing operations	130		162		311	353
Earnings from discontinued operations, net of income taxes (5)	0		65		0	123
Net earnings	130		227		311	476
Dividends on preference shares	0		0		0	(22)
Net earnings attributable to Weyerhaeuser common shareholders	130		227		311	454
Charges for impairment of assets					153	23
Charges for product remediation	(190)		0		(240)	0
Intersegment eliminations
Segment Reporting, Revenue Reconciling Item [Line Items]
Intersegment sales	(179)		(233)		(544)	(692)
Operating segments
Segment Reporting, Revenue Reconciling Item [Line Items]
Net contribution to earnings	218		307		752	831
Unallocated items
Segment Reporting, Revenue Reconciling Item [Line Items]
Net contribution to earnings	(17)		(9)		(113)	(91)
Timberlands
Segment Reporting, Revenue Reconciling Item [Line Items]
Sales to unaffiliated customers	491		484		1,446	1,342
Intersegment sales	179		216		544	631
Net contribution to earnings	131		122		267	376
Charges for impairment of assets				$ 147
RE & ENR
Segment Reporting, Revenue Reconciling Item [Line Items]
Sales to unaffiliated customers	82		48		181	125
Net contribution to earnings	47		15		96	42
Wood Products
Segment Reporting, Revenue Reconciling Item [Line Items]
Sales to unaffiliated customers	1,299		1,177		3,746	3,302
Intersegment sales	0		17		0	61
Net contribution to earnings	40		$ 170		389	$ 413
Charges for product remediation	$ (190)	$ (50)			$ (240)